So, Linux is an alternative to operating systems like Microsoft Windows and Mac OS, except:

It is generally free of cost.

And comes with lots of programs you would normally have to spend more money on.

And is essentially free from viruses.

And is constantly being updated.

Linux doesn't belong to anyone, so there are many different versions
of it designed for lots of different sorts of people. If you have never
tried Linux you will want to start with a distribution that is easy to
use.

Linux Distributions

Imagine a kid in a candy store - and all the lollies are free. The
mouth waters. The mind boggles. So many options. So many taste
combinations. Where do a start? How long can I stay?

Now imagine a geek in his electronic equivalent. A free operating
system. Tens and hundreds of thousands of free programs. All freely
available from the internet. All customisable. And you can share them
all freely with your friends. What is the ideal combination of programs
he can put together? What is the coolest look? What will his friends
think?

Or imagine a company trying to put together the most effective and
stable collection of applications they can - either for themselves, or
to share with other companies. Out of all of the available programs,
only so many will fit on the CD they are sharing. What are the best
programs to choose?

This is what a Linux distribution (distro) is: A customised version
of Linux combined with a set of free programs put together by an
individual, a community, or a company.

Different distros may also have different "flavours", different
installation methods, differerent ways of updating software, and
different interfaces. Some are designed for specific groups of people
to help with specific jobs (e.g. recording studios, scientists, playing
back movies and multimedia), while other distros are more general.